Watch: 'Raining hay' - Incredible moment 'dust devil' scatters hay bales over Auckland skies

Aucklanders may see hay bales falling from the sky today after a "dust devil" in West Auckland ripped through a field, sending debris hundreds of metres into the air.

Agricultural worker Blake Howard was working on Old North Rd in Kumeu late Tuesday morning when he turned around and saw hay bales taking off.

Howard pulled out his phone and started recording, capturing the incredible moment the bales were swallowed up and spat out by a passing twister.

The worker's footage shows the hay bales breaking up and being spun around like a washing machine.

He told the Herald he'd never seen anything like it.

"Some people would have had hay raining down on them and had no idea why." Photo / Blake Howard

"I was just baling like I normally do and looked behind me and saw all this hay in the air," he said.

"I've seen it a couple of times but this was huge. I've never seen anything this size.

"When I was videoing the hay went about 200m in the air. After filming, it started going higher up, maybe 600m in the sky and started going over towards Auckland City.

"Some people would have had hay raining down on them and had no idea why.

"It just took off and went over the road and spread out everywhere. It was pretty crazy."

A MetService spokesperson told the Herald the 'Dust Devil" is not to be mistaken for a tornado.

"What you are seeing is a Dust Devil. In most cases they are very harmless.

"These Dust Devils can form when the surface is very hot and there is an absence of wind. They are not to be mistaken for a tornado, which only occur with severe thunderstorms.

"Dust Devils like this can form on any day that is very hot and with very little wind. It's just the hot air rising from the surface."

There have been no reports of any damage from the twister, or its debris.